cpu_list_fills

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description fully carries the burden of behavioral disclosure. It states it is a 'Public read' (safe, no auth), explains one-way paging (newest first, `before` cursor pages down), the absence of a 'since' parameter, and how to read new data without paging down. It also clearly discloses the limitation on filtering by buyer/seller.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is long but every sentence carries essential information: definition, semantics of fills, filtering options, paging rules, limitations, and alternatives. It is front-loaded with the core purpose, uses capitalization to highlight the paging note, and contains no fluff or redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's complexity, the lack of annotations, and absence of an output schema, the description is remarkably complete. It explains what constitutes a fill, how to page correctly, how to use filters, what the tool cannot do (e.g., filter by buyer/seller), and how it relates to sibling tools. While it doesn't enumerate the exact output fields, it provides enough context about the cursor and semantics to make the tool usable.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema already has detailed descriptions for all 4 parameters (100% coverage), so the baseline is 3. The description adds extra meaning beyond the schema, particularly for the `before` cursor by explaining the one-way paging direction and the strategy of reading the head to detect new fills. It also clarifies that filters are optional and combinable, but does not add much for `limit` or `hubTokenId` beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose: 'The feed of executed buys (fills) — what buyers actually PAID, not what sellers ask.' It uses a specific verb+resource and distinguishes itself from siblings like cpu_get_markets (asks) and cpu_list_lots (lots).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides explicit usage guidance: it tells when to pair with cpu_get_markets to compare asks vs. real prices, and directs users to cpu_list_my_lots for their own trades since this feed cannot filter by buyer/seller. It also explains how to page correctly and what not to do.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.